1) Adjusters of pianos 2) Broadcast signal receivers 3) Car radio buttons 4) Carnegie Hall workers 5) Certain pianists 6) Folks fiddling with keys 7) Machineheads 8) Parts of radio receivers 9) Parts of radios 10) Piano fixers 11) Piano men 12) Piano workers 13) Radio knobs 14) Radio parts 15) Radio receiver parts 
machineheads